Multiple unit mine cable cutter



51m@ 20, 3%? M. KURTZ 3,326,3523

MULTIPLE UNIT MINE CABLE CUTTER Filed April 30, 1956 3 Sheets-Sheet l y. Il Winni-Wam 1lIIIIIIHIIIIII"IlIIIIIIIIIIllllllllllllllllillillllllllllmll [ml'dllllll nuum IIIIIIIII 1N VENTOR ATTORNEY M, KURTZ 3,326,173

MULTIPLE UNIT MINE CABLE CUTTER Filed April ISO, 1956 5 Sheets 5heet 2 IN VENTOR 58 NK WiL/TZ ATTORNEY me 20, w67 M KURTZ '3,326,173

MULTIPLE UNIT MINE CABLE CUTTER Filed April 30, 1956 5 SheeJS--Sheeil .3

Fm FPL/20 1N VENTOR MARK KU@ TZ ATTORNEY United States Patent O 3,326,173 MULTIPLE UNIT MINE CABLE CUTTER Mark Kurtz, Washington, D.C., assigner to the United States of America as represented by the Secretary of the Navy Filed Apr. 38, 1956, Ser. No. 581,811 8 Claims. (Cl. 114-221) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to an underwater cable cutter actuated by explosive means, and more particularly relates to a cable cutter pulled through the water by a sweep line carried by mine sweeping vessels, said cutter being adapted to sever the cable by which an explosive mine is anchored in the Water.

Mine cable cutter devices are well known and usually are used in conjunction with sweep lines towed by minesweeping vessels. However, in the prior art the number of cutters that can be installed on a sweep line per unit length thereof is limited because individual cutters are spaced along the sweep line and each cutter is quite heavy. Consequently the number -of mine anchor cables that can be cut per given length of sweep line is similarly limited, necessitating rearming of the cable cutters at frequent intervals, and impeding the rapid sweeping of an area heavily infested with explosive mines. An object of the invention is to overcome the foregoing and other disadvantages of the prior art.

An object of the invention is to provide a mine cable cutter or cutting tool of the explosive type which is light in weight, which is simple in construction, and which is improved in operation,

A further object of this invention is to provide a mine cable cutter design and arrangement lwhich makes it possible to attach a greater number of the cutters to a given length of sweep line.

Still another object is to provide a mine anchor cable cutter with -a fool-proof trigger mechanism actuated only upon contact with said cable.

In addition, it is an object of this invention to provide a cable cutter that is less subject to fouling due to underwater debris and the like than the prior art cutters, and which cannot be accidently discharged while the cutter is out of the water.

A still further object is to provide a cable cutter with an -anvil member that is not likely to be broken away except upon discharge of the cutter mechanism.

Still another object is to provide a cable cutter mechanism that is simple in construction and that can lbe used repeatedly at little expense and with a minimum of effort and training.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. l is a view showing a plurality of cutters made according to this invention and attached to a mine sweep line;

FIG. 2 is an end view of the assembly shown in FIG. 1 looking from the left;

FIG. 3 is a sectional View taken on line 3-3 of FIG. 1;

FIG. 4 is a longitudinal sectional view of an individual cutter shown in loaded and cocked condition;

FIG. 5 is a side view of the cutter looking from the left in FIG. 4;

FIG. 6 is a sectional View of the cutter taken on line 6 6 of FIG. 4;

FIG. 7 is a sectional view of said cutter taken on line 7--7 of FIG. 4;

FIG. 8 is a vertical sectional view, partially broken away, of the upper portion of the cable cutter mechanism at the beginning of its cutting operation;

FIG. 9 is la horizontal sectional view on line 9--9 of FIG. 8; and

FIG. 10 is a sectional view taken on line 10-10 of FIG. 8, but showing the cutting operation at a stage somewhat more advanced than that of FIG. 8.

Referring now t-o the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. l a view of an assembly of four mine cable cutters or cutting tools 20 on a mine sweep line 22. It is pointed out that all of said cutters or tools are substantially identical.

As shown in lFIG. 4, each cutting tool 20 comprises a frame 24. The part of said frame adapted to be located toward the far or trailing end of -a sweep line has a cylindrical hole or barrel 26 formed therein; and a cutting chisel 28 is slidably mounted in said barrel. The chisel 28 comprises a cutting mechanism, and is held in fixed position by a shear pin 30 that passes through alignable holes in both the frame and the chisel. Extending from the lower end of the barrel is a chamber 32, said chamber being `adapted to receive a cartridge 34 therein. The cartridge 34 therein. The cartridge 34 is utilized to fire the cutting mechanism comprising the chisel 28 forwardly in a manner hereinafter set forth.

An anvil 36 is fastened to the forward part of the frame 24 and has a forward portion thereof spaced from and extending across the forward end of said barrel. The forward portion of the anvil 26 is adapted lto confine a mine cable in a position to be struck and cut by the chisel 28 during operation of the cutter. The anvil 36 is provided with a shank member 38 at the rear thereof having a leading face 42 which is in line with one wall of the barrel 26. The shank member is reduced in thickness near its lower end to provide a tenon that tits within a notch provided in the frame 24. The shank 38 is held onto the frame 24 by a screw-type shear pin 40 which passes through both the frame and said tenon as shown in FIG. 6, and is threaded in the shank only. The anvil member 36 is restrained against a tendency to rotate about shear pin 40, by virtue of the abutment of a lower portion of leading face 42 of the shank 38 against a side portion of the'chisel 28, as shown in FIG. 4. The abutting surfaces of the anvil 36 and frame 24 have a substantial area of contact and are interlocked by the tenon and notch construction, so that accidental breaking away of said anvil from the frame by snagging or the like is unlikely. A further antisnagging feature resides in the forward surface 4S of the anvil 36 being substantially flat and smooth so as also toiavoid entanglement with an extraneous object.

The anvil 36 is in a sense hook-shaped with a leading face 50 inclined inwardly toward a recess 52'of the anvil 36 that faces the forward end of the frame 24. The inclined face 50 is adapted to guide a mine cable into the space between the recess 52 and the front end of the frame 24 for positioning a snared mine cable so that the cable can be cut by the cutting chisel 28 moving toward the anvil 36; said position being shown in FIG. 10 for example. The curved recess 52 helps to hold the mine cable in cutting position.

The mine cable is cut by the chisel 28 when the chisel is forced toward the anvil 36 by discharge of the cartn'dge 34 carried at the lower extremity of the frame 24. The cartridge is discharged by firing mechanism located at the lower end of the frame. The firing mechanism comprises a breech block 54 having therein a bore 56 axially aligned with the chamber 32 in which the cartridge 34 is carried. The bore 56 is closed at the end thereof adjacent the cartridge chamber 32, except for a small hole 58 through which a firing pin 60 is adapted to move and strike the base of the cartridge 34. The lower portion of the firing pin 60 is provided with four laterally extending webs 62 arranged at right angles. The webs slidably engage the wall of the bore 56 below said small hole 58. The firing pin 60 is normally held in retracted position, as shown in FIG. 4, by a spring 64 compressed between the respective upper ends of the webs 62 and the forward end wall of the bore 56. Two oppositely disposed webs 62 extend rearwardly to a pivotal connection 66 with one end of a lever 68 located in a slot 70 in the breech block 54. Intermediate its ends said lever is pivotally connected to said breech block by a point pin 72. The lever 68 and breech block are provided with aligned holes 74 through which a safety rod or pin 76 may be passed for latching the lever against pivoting about pivot pin 72 so as to prevent accidental ring of the mechanism by accidental pivoting of said lever 68. The other end of the lever 68 has a piston 78 pivotally connected thereto which extends forwardly in a cylinder 80 in the breech block 54, said piston being slidable within said cylinder. The cylinder 80 is located at the side of the breech block opposite the bore 56 and is parallel therewith. Thus it will be seen that a rearward movement of the piston 78 will bring about the tiring of the cartridge by rotating the lever 68 about its pivot'and forcing the tiring pin 60` forwardly against the cartridge 34.

The breech block 54 is held in contact with the rear end of the main frame 24 of the cutter by being fastened to a side extension 82 of said frame, said extension having a turned rear end portion 84 abutting the rearmost portion of the breech block, as indicated in FIGS. 4 and 5. The breech block is removably attached to the frame by a screw 86 threaded into a hole in the extension 82.

In axial alignment with but spaced from the piston cylinder 80 the frame 24 of the cutter is further provided with a plunger 88 having a rear end portion adapted to enter the cylinder 80. The plunger 88, however, cannot move far enough to contact the piston 78. When the assembly is submerged in water, water fills the vremaining space in the cylinder 80 in which the piston 78 is situated, and thus rapid rearward movement of the plunger 88 into the cylinder 80 forces water against the piston. The force of the moving plunger 88, acting through the water, forces the piston 78 rearwardly, thereby moving the firing pin 60 forwardly against the cartridge 34, discharging the latter. The explosion drives the chisel member 28 toward the anvil 36 for cutting action.

In order to precent fouling of the piston cylinder 80 by underwater debris, a hole 90 is provided in the under wall of the frame to insure a free flow of water past the mouth of the cylinder, when the tool is submerged.

The plunger 88 has a sleeve 92 rigidly xed thereto adjacent its forward end, said sleeve and plunger being slidable in a passage 94 having the same shape as said sleeve, for example, hexagonal. A collar 96 having a central hole is snugly mounted in the plunger passage to properly guide the plunger and insure proper alignment thereof with the piston cylinder 80. The collar 96 is carried in a slot in the frame 24, the collar having a shoulder 98 at one end to further limit movement thereof. The rearmost end of the cylindrical plunger 88 slides within the circular opening provided in said collar.

A rod 100 is fastened to the forward face of the sleeve 92 and extends forwardly across a recess 102 in the side of the cutter frame 24. The rod 100 has a forward end slidably mounted in a hole 104 provided in a protrusion in the forward part of the frame. The forward end of the rod 100 has a hole 106 therein extending transversely of the axis of the rod for a purpose hereinafter set forth. One or more springs 108 surround the rod 100 and are normally under compression between the sleeve 92 and the under surface of the said protrusion, thereby tending to urge the plunger 88 rearwardly toward the piston.

The plunger 88 is normally held in retracted position against the action of the springs 108 by means of a wirelike, S-shaped trigger pin 110', FIG. 4. The rearmost leg 111 of the trigger pin normally is partially situated within a transverse groove 112 provided in the forwardend of the frame 24. It is pointed out that the groove 112 has an enlarged portion 113 at that end thereof adjacent to the barrel 26 that carries the chisel 28. The rearmost leg 111 of the trigger pin 110 that normally lies in the groove 112 has lan offset portion situated within the en larged portion 113 of the groove whereby that part of the rearmost leg portion that crosses the barrel 26 is offset with respect to the axis of the chisel member; as better shown in FIG. 6. The rearmost leg 111 of the trigger pin is provided with a smaller latching element or extension 114 at its free end, said extension being adapted to enter the hole 166 in the forward end of the rod 100, thereby retaining said rod in retracted position, against the action of spring 108, in the manner shown in FIG. 4.

The rearmost leg 111 of the trigger pin 110 extends across the opening in which the chisel 28 is carried to a point substantially adjacent the face 42 of the shank portion 38 of the anvil 36, said shank portion adjacent the trigger pin being provided with a cut-away area 116 that is deeper than the thickness of the trigger pin. At the portion of the trigger pin adjacent the shank member 38, the trigger pin is provided with a bend at substantially right angles to leg 111, and thence to provide an intermediate cross portion that extends toward the hook portion of the anvil. The cross portion extends to another right angle bend in the pin 110; and from this bend the pin has a forwardrnost leg 117. The forwardmost leg 117 of said trigger pin 110 is long enough to extend into a hole 118 extending transversely of the shank member 38, said hole being of a -diameter that is greater than the maximum thickness of the leg 117 of the trigger pin so as to allow some transverse play of the pin in the hole 118. The trigger pin is prevented from turning in the frame by virtue of the offset portion of the rearmost leg being located in the enlarged portion 113 of the forward portion of the frame.

The narrower extension 114 at one end of the pin 110 provides a shoulder 119 that in cocked position of the cutting tool as shown in FIG. 4 abuts the top part of the rod 104, so that the movement of the pin 110 will be guided at the start when the cutting tool is submerged in water and a mine cable line such as 120 is snared.

Assuming that the cable line 120 is snared, the face 50 of the tool cams the line toward the recess 52 in the anvil 36. The line strikes the trigger pin 110` and in the manner shown in FIGS. 8 and 9, pushes the trigger pin Y toward the shank 38 of the anvil. The extension 114 leaves the hole 106 in the rod member 100, permitting the coil springs 108 to drive the plunger 88 rearward toward the breech block 54 and towards the cylinder 80 in which the piston 78 is located. The water in said cylinder is pushed by the plunger and being incompressible drives the piston rearwardly, rocking the lever 68 about pin 72, thereby driving the tiring pin 60 forwardly. The forwardly moving pin 60 discharges the cartridge 34 so that the chisel 28 is forcefully driven forwardly toward the anchor line 120` and the anvil 36. As the chisel moves forwardly, one of its beveled surfaces strikes an edge of the offset portion of the trigger pin in the manner shown in FIG. 9, thereby turning the trigger pin about its forward leg 117 in hole 118, and also tilting it forwardly as shown in broken lines in FIG. 8. It is ponited out that the rearmost leg 111 of the trigger pin is pushed far enough forward to clear the upper side edges of the groove 112, as shown in FIG. 8, so that the face of the chisel may rotate the trigger pin completely out of the path of the chisel in the manner shown in FIG. 10. The chisel will not strike the forwardly extending portion of the trigger pin because the'movement of the cable line 120 forces said portion into the recessed area 116 in the shank of the anvil, as shown in FIG. 8. After cutting the cable, the edge of the chisel strikes the anvil 36. The drive of the chisel is adequate to cut the cable and shear off the screw 40, .and thus break the anvil away from the frame. Thus it can be seen that when a cutter is red, the anvil is lost, thereby preventing the snagging of another mine cable by a cutter that has already vbeen fired. The lost anvil can readily be replaced with another one for rearming the cutter when the sweep line is hauled in. It is pointed out that accidental discharge of the cutter tool by underwater debris or the like striking the trigger pin, is prevented by virtue of the fact that the anvil is substantially thicker than the trigger pin yand hence acts as a shield therefor, as can be seen in FIG. 5.

In the event that the trigger pin is accidently removed from hole 106 prior to placing the device underwater so that passage 94 is air-filled, the plunger will not strike the piston, as the movement thereof will be stopped when the sleeve 92 strikes the coller 96 contained within the plunger passage 94. This stopping position is reached before the plunger 8S reaches piston 78. As a further precaution, the aligned holes provided in the lever 68 within the breech block and in the cover of the breech block are adapted to receive the -safety pin 76 that will prevent rotation of said lever. Prior to placing the mechanism within the water, the safety pin is withdrawn.

One advantage of the structure described above is that it results in a compact, light-weight cable cutter, wherein the parts are so arranged as to make possible the use of a greater number of such cutters per given length of mine sweep line. Specifically, the above described cutter has approximately one-fourth the weight of the standard cutter used heretofore, and shown in Patent No. 2,422,506. One arrangement of cutters on a sweep line is shown in FIG. 1 wherein four cable cutters are shown attached to a single conventional carrier member, said carrier member being clamped to a sweep line 22. The cutter at the extreme left is shown in Adischarged condition with its anvil lost or spent.

The carrier member consists of a base plate 122 having afiixed thereto a stabilizing fin 124 extending laterally therefrom, said fin member being adapted to maintain the combination of cutters in a horizontal Iplane as they are swept through the water. A U-shaped member having a crosspiece 126 and legs 130 is carried by the base plate. The crosspiece 126 is aixed to, and extends lengthwise of, said base plate 122, and the rearmost ends of the respective cable cutters abut said crosspiece and are bolted thereto by bolts 128 extending into holes in the end portions 84. The legs 130 extend outwardly of the base plate 122 adjacent the forward end thereof. The forward leading edge of the base plate 122 is also provided with a ange 131 extending outwardly therefrom and adapted to deflect a mine anchor cable into the path of one of said hooks.

The first cable cutter abuts a leg 130- as well as the longitudinal crosspiece 126, the various cutters being placed in abutting relation to one another, as shown in FIG. l. The base plate 122 is adapted to be attached to the sweep line 22 by means of two or more U-shaped clip members 132 in the manner shown in FIG, 2, a toggle bolt 134 extending through the legs of said U-shaped member and the base plate with the cable being located between said bolt and the bite of the U-shaped clamp.

The compact arrangement shown in FIG. 1 is made possible not only by virtue of the compactness of each cutter and its light weight, but also by the fact that each cutter is 4so oriented on the base plate 122 that when said base plate is attached to the mine sweep line 22 said cutter extends substantially at right angles to said sweep line. As a result of orienting the cutters in the manner described above each anvil 36 is so arranged that its hook portion faces lengthwise of the sweep line instead of longitudinally thereof as has been the case heretofore. Consequently, the cutters successively become active for mine cable cutting operations. It is further pointed out that the shank of one anvil is in abutting relation with the frame of an adjacent unred cutter and hence when a chisel strikes the anvil, said anvil will be driven forwardly and then away from the cutter frame, thus preventing same from striking any adjacent anvil and thus preventing accidental dislodgement of another anvil. With the last cutter of the group, this precaution is not essential.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise that as specifically described.

What is claimed is:

1. A mine cable cutter comprising an elongated frame having a hook-shaped member attached to the forward end thereof, said hook-shaped member having a shank portion attached to the frame by means of a shear pin, and an anvil portion extending across the forwardmost end of the frame and spaced from said end thereby forming a mine cable receiving recess, a cutting member slidably mounted in said frame and adapted to slide towards said anvil striking the same, an explosive cartridge mounted behind said cutting member for driving same towards the anvil for cutting a cable received in said recess, means actuated by a mine cable for firing said cartridge, including a slidable rod mounted on said frame, spring means for moving said rod, means for retaining said rod against movement by the spring, said rod retaining means being adapted to be moved out of engagement with said rod upon entry of an anchor line into said recess, said rod retaining means comprising an S-shaped trigger-pin, said trigger-pin comprising a rearmost leg resting within a groove provided in the forward end of the frame, a portion of said rearmost leg being removably engaged within a hole provided in the forwardmost end of the rod, said groove having a widened portion therein adjacent one of its ends and said rearmost leg having an offset portion resting in said widened groove portion, thereby preventing rotation of said trigger-pin about the rearmost leg; said trigger-pin further comprising a forwardly extending portion connected to the rearmost leg and having at its forward end a forwardmost leg extending substantially at rightV angles to the forwardly extending portion of the pin, said forwardmost leg extending into a hole provided in the shank portion of the hookshaped member whereby said trigger-pin is retained against rotation about the axis of the rearmost leg of said trigger-pin, said rearmost leg of the trigger-pin being adapted to be withdrawn from the hole provide-d in said rod by the movement of an anchor line against the forwardly extending portion of the trigger-pin, thereby allowing said rod to move rearwardly on the frame actuating the firing mechanism and discharging the cartridge thereby causing forward movement of the cutting member.

2. A mine cable cutter as set forth in claim 1 wherein the offset porti-on of the rearmost leg of the trigger-pin extends across the path of movement of the cutting member, said 'cutting member being provided with beveled surfaces at its forward end adapted to deflect said rearmost leg of the trigger-pin out of its path of movement.

3. A mine cable cutter comprising an elongated frame member, an anvil member attached to said frame at its forwardmost end in spaced relation therefrom thereby forming a mine cable receiving recess, a chisel member slidably mounted in said frame and movable toward said anvil member being adapted to strike the same, an explosive cartridge mounted behind said chisel member, means for firing said cartridge whereby the chisel will be driven forwardly against the anvil, said firing means comprising a breech block snugly mounted against the rear end of the frame, a firing pin slidably mounted in said breech `block and having its rearmost end pivotally attached to one end of a lever that is pivoted intermediate its ends to said breech block, a piston slidably mounted within a cylinder provided in the breech block on the same side of the lever as the firing pin and having its rearmost end pivotally connected to the opposite end of said lever; an opening in said frame at the forward end of said cylinder for admitting water therein when the cutting tool is submerged, a plunger slidably mounted on said frame in axial alignment with said cylinder and piston spring means adapted to drive said plunger into said cylinder pushing water against the forward face of the piston, thereby rocking the lever and pushing the tiring pin forwardly against the cartridge, discharging the same, means for preventing the plunger from striking the forward face of the piston, a sleeve member attached to the forward end of the plunger, a rod extending forwardly from said sleeve and having a forward end slidably mounted on said frame, said spring means surrounding said rod and bearing against said sleeve, tending to push the plunger rearwardly toward the piston; means for retaining the plunger in retracted position, comprising a hole in the forward end of said rod, a slot provided in the forward end of said frame and having an enlarged portion therein, an S-shaped trigger-pin having a rearmost leg carried in said slot and having a portion of said leg engaged in a hole in the rod thereby retaining said rod in retracted position, said trigger-pin having an offset portion in its rearmost leg for preventing accidental rotation thereof, said trigger-pin further comprising a forwardly extending portion and a forwardmost leg portion extending at right angles to said portion, said forwardmost leg portion extending into a hole provided in a shank portion lon said anvil, the rearmost leg portion of the trigger-pin being situated in the path of movement of the chisel member but offset from the center line thereof, said trigger-pin being adapted to be moved laterally of the frame by the entrance of an anchor line into said recess, thereby removing the rearmost leg of the pin from the hole provided in the rod member, allowing rearward movement of said rod and plunger, thereby actuating the tiring mechanism; whereby said chisel member in its forward movement is adapted to contact the rearmost leg of the trigger-pin pushing the same forwardly out of the `groove in the for* ward end of the frame and rotating the trigger-pin about its forwardmost leg thereby preventing said trigger-pin from blocking the forward movement of the chisel member.

4. A mine cable cutter comprising an elongated frame, a barrel provided in said frame adjacent one side thereof and opening at one end of said frame; a hook-shaped member attached to the frame adjacent said end, said hook-shaped member comprising a shank portion attached to a side of said frame and extending forwardly thereof, said hook-shaped member further comprising an anvil portion extending from said shank portion across and spaced from the adjacent end of said frame, thereby forming a mine cable receiving recess between said anvil and said frame, a cutting member slidably mounted in said barrel adjacent the side where the shank yportion is attached to the frame, explosive means for forcibly driving said cutting member across said cable receiving recess and against said anvil; actuating means for discharging said explosive means, a trigger-pin releasably engaged with said actuating means for retaining said means in an inoperative position, said trigger-pin comprising an arm extending ltransversely of said recess and longitudinally of the path of travel of said cutter member, said arm being adapted to be moved by a mine cable as said cable moves through said recess so as to release said triggerpin from said actuating means, whereby said explosive means is discharged; said trigger pin further comprising an extension aiiixed |to one end of said arm and extending at right angles to said arm and longitudinally of said mine cable receiving recess, an aperture formed in said shank portion for receiving a portion of said extension,

said extension and said aperture in said shank portion being relatively proportioned so that said trigger pin is adapted |to be withdrawn from the actuating means retaining position upon accidental breaking away of said hook member from said frame.

5. A mine cable cutter comprising an elongated frame having a hook-shaped member attached to the forward end thereof, said hook-shaped member having a shank portion attached to the frame by means of a shear pin, and an anvil portion extending across the forwardmost end of the frame and spaced therefrom thereby forming a mine cable receiving recess, a cutting member slidably mounted in said frame and adapted to slide across said recess and into contact with said anvil striking the same, explosive means mounted behind said cutting member for driving the same towards the anvil for cutting a mine cable received in said recess, means including a firing mechanism actuated by a mine cable for ring said explosive means, including a slidable rod mounted on said frame, spring means for moving said rod, means for retaining said rod against movement by the spring, said rod retaining means being adapted to be moved out of engagement with said rod upon entry of a mine cable into said recess, said rod retaining means comprising a trigger pin, said trigger pin comprising a rear-most leg extending longitudinally of said cable receiving recess, said rearmost leg having a portion thereof Iremovably engaged with a hole provided in the forwardmost end of said rod, said trigger pin further comprising a forwardly extending portion extending at right angles to said rearmost leg and connected to the reannost leg, said forwardly extending portion being located substantially in a line with the axis of said cutting member and substantially within the path of movement thereof, an extension affixed to the forwardly extending portion of the trigger pin and extending at an angle thereto, an aperture formed in said hook shaped member for receiving an end portion of said extension, whereby resistance to twisting of the trigger pin about the rearmost leg thereof is imparted thereto; the rearmost leg of the trigger pin vbeing adapted to be withdrawn from the hole provided within said rod by the movement of a mine cable against the forwardly extending portion of the trigger pin, thereby allowing said rod to move rearwardly on the frame actuating the explosive means thereby causing forward movement of the cutting member; said cutting member being driven forwardly with a force suicient to cut a cable, and strike said anvil, breaking said shear pin thereby releasing said hook shaped member from said frame.

6. A mine cable cutter assembly comprising, a baseplate, attaching means on said base-plate adapting the same for attachment to a towed mine sweep line, a plurality of cutter tools attached to said base-plate, said cutter tools `being arranged in tandem on said base-plate, one behind the other, and extending at right angles to a mine sweep line when said base-plate is attached thereto, each cutter tool comprising an elongated frame having a hook-shaped member attached to the forward end thereof, said hook-shaped member having a shank portion attached to the frame by means of a shear pin, and an anvil portion extending across the forwardmost end of the frame and spaced therefrom thereby forming a mine cable receiving recess, a cutting member slidably mounted in said frame and adapted to slide across said recess and into contact with said anvil striking the same, explosive means mounted 'behind said cutting member for driving the same towards the anvil for cutting a mine cable received in said recess, means including a tiring mechanism actuated by a mine cable for firing said explosive means, including a slidable rod mounted on said frame, spring means for moving said rod, means for retaining said rod against movement by the spring, said rod retaining means being adapted to -be moved out of engagement with said rod upon entry of a mine cable into said recess, said rod retaining means comprising a trigger pin, said trigger pin comprising a rear-most leg extending longitudinally of said cable receiving recess, said rearmost leg having a portion thereof removably engaged within a hole provided in the forwardmost end of said rod, said trigger pin further comprising a forwardly extending portion extending at right angles to said rearmost leg and connected to the rearmost leg, said forwardly extending portion being located substantially in a line with the axis of said cutting member and substantially within the path of movement thereof, an extension axed to the forwardly extending portion of the trigger pin and extending at an angle thereto, an aperture formed in said hookshaped member for receiving an end portion of said extension, whereby resistance to twisting of the trigger pin about the rearmost leg thereof is imparted thereto; the rearmost leg of the trigger pin being adapted to be withdrawn from the hole provided within said rod by the movement of a mine cable against the forwardly extending portion of the trigger pin, thereby allowing said rod to move rearwardly on the frame actuating the explosive means thereby causing forward movement of the cutting member, said cutting member being driven forwardly With a force sufficient to cut a cable, and strike said anvil, breaking said shear pin thereby releasing said hookshaped member from said frame.

7. A mine cable cutter assembly comprising, a baseplate having means thereon for selective attachment of the assembly to a towed mine sweep line, a plurality of cutter tools removably attached to said base-plate in tandem relation with one another, each of said cutter tools extending substantially at right angles to said sweep line when said base-plate is attached to the latter, each of said cutter tools comprising an elongated frame member extending transversely of said sweep line, a hook member having a shank portion attached to said frame member with a shear pin, at the end thereof nearest said sweep line and having an anvil portion extending transversely of said frame member in spaced relation from the adjacent end thereof, thereby forming a mine cable receiving recess, each of said hook members being attached to its respective frame by means of a shear pin, a cutter member slidably mounted on said frame adjacent that side of the frame nearest the closed end of said mine cable receiving recess, explosive means mounted in said frame for forcibly driving the cutter member toward said anvil portion with su'icient force to cut a mine cable received in said recess, strike said anvil portion and break the same away from said frame; actuating means for firing said explosive means including a rod, said actuating means slidably mounted and spring biased on said frame adjacent the side thereof nearest the open end of said mine cable receiving recess, a trigger pin having a portion thereof engaged with said rod for restraining the latter against operative movement, said trigger pin being located in said mine cable receiving recess and adapted to be actuated by a mine cable, said trigger pin having a forwardly extending portion situated in the path of movement of said `cutter and located adjacent the closed end of said mine cable receiving recess, an extension aixed to the forwardly extending portion of the trigger pin and extending at an angle thereto, an aperture formed in said hook shaped member for receiving an end portion of said extension, whereby resistance to twisting of the trigger pin about the portion thereof engaged with said rod is imparted thereto; said trigger pin being removed from restraining engagement with said actuating means Iby the movement of a mine cable into said recess against said forwardly extending portion thereby rendering said actuating means operative for discharging said explosive means.

8. A mine cutter cable assembly comprising, a baseplate having means thereon whereby the assembly may be attached to a towed mine sweep line, a plurality of cutter tools removably attached to said base-plate in tandem relation with one another, each of said cut-ter tools extending substantially at right angles to said sweep line when said base-plate is attached to the latter, each of said cutter tools comprising an elongated frame member, a hook shaped member having a shank portion thereof attached to said frame adjacent one side thereof by means of a shear pin, whereby a mine cable receiving recess is formed at one end of said cutting tool, a cutter member slidably mounted on said frame for movement longitudinally thereof, said cutter member being mounted adjacent that side of the frame nearest the shank portion of said hook shaped member, explosive means for driving said cutter member across said mine cable receiving recess and against lan anvil portion of said hook-shaped member; actuating means including a slidable rod, for tiring said explosive means, said rod being slidably mounted on said frame for movement longitudinally thereof adjacent that side of the frame nearest the open end of said mine cable receiving recess, a trigger pin removably engaged with said rod and retaining said rod and therefore said actu-ating means in inoperative position, said trigger pin having a first portion thereof extending toward the closed end of said recess and having a second portion adjacent said closed end of the recess extending at right angles to said first portion and transversely of said recess, an extension affixed to the end of the second portion of the trigger pin and extending at an tangle thereto, an aperture formed in said hook shaped member for receiving [an end portion of said extension, whereby resistance `to twisting of the trigger pin about the first portion thereof is imparted thereto; said second portion being adapted to be engaged by a mine cable upon movement of the latter into said mine cable receiving recess, whereby said trigger pin is disengaged from said actuating means thereby causing said actuating means to discharge said explosive means, `driving said cutter member across said mine cable receiving recess and into cont-act with the anvil portion of the hook shaped member, thereby cutting a mine cable and dislodging said hook shaped member from said frame, whereby an unfred successive one of said ftandemly arranged cutter tools is adapted for engagement with a successively encountered mine cable.

References Cited UNITED STATES PATENTS 1,304,549 5/1919 Du Pont 89-1 1,312,405 8/1919 Lander 114-221 2,420,987 5/ 1947 Temple 89-1 2,422,506 6/ 1947 Temple 114-221 2,800,868 7/1957 Temple 89-1 X 2,806,442 9/1957 Temple 89-1 X MILTON BUCHLER, Primary Examiner.

SAMUEL BOYD, ARTHUR M. HORTON, Examiners.

S. W. ENGLE, B. BELKIN, Assistant Examiners. 

1. A MINE CABLE CUTTER COMPRISING AN ELONGATED FRAME HAVING A HOOK-SHAPED MEMBER ATTACHED TO THE FORWARD END THEREOF, SAID HOOK-SHAPED MEMBER HAVING A SHANK PORTION ATTACHED TO THE FRAME BY MEANS OF A SHEAR PIN, AND AN ANVIL PORTION EXTENDING ACROSS THE FORWARDMOST END OF THE FRAME AND SPACED FROM SAID END THEREBY FORMING A MINE CABLE RECEIVING RECESS, A CUTTING MEMBER SLIDABLY MOUNTED IN SAID FRAME AND ADAPTED TO SLIDE TOWARDS SAID ANVIL STRIKING THE SAME, AN EXPLOSIVE CARTRIDGE MOUNTED BEHIND SAID CUTTING MEMBER FOR DRIVING SAME TOWARDS THE ANVIL FOR CUTTING A CABLE RECEIVED IN SAID RECESS, MEANS ACTUATED BY A MINE CABLE FOR FIRING SAID CARTRIDGE, INCLUDING A SLIDABLE ROD MOUNTED ON SAID FRAME, SPRING MEANS FOR MOVING SAID ROD, MEANS FOR RETAINING SAID ROD AGAINST MOVEMENT BY THE SPRING, SAID ROD RETAINING MEANS BEING ADAPTED TO BE MOVED OUT OF ENGAGEMENT WITH SAID ROD UPON ENTRY OF AN ANCHOR LINE INTO SAID RECESS, SAID ROD RETAINING MEANS COMPRISING AN S-SHAPED TRIGGER-PIN, SAID TRIGGER-PIN COMPRISING A REARMOST LEG RESTING WITHIN A GROOVE PROVIDED IN THE FORWARD END OF THE FRAME, A PORTION OF SAID REARMOST LEG BEING REMOVABLY ENGAGED WITHIN A HOLE PROVIDED IN THE FORWARDMOST END OF THE ROD, SAID GROOVE HAVING A WIDENED PORTION THEREIN ADJACENT ONE OF ITS ENDS AND SAID REARMOST LEG HAVING AN OFFSET PORTION RESTING IN SAID WIDENED GROOVE PORTION, THEREBY PREVENTING ROTATION OF SAID TRIGGER-PIN ABOUT THE REARMOST LEG; SAID TRIGGER-PIN FURTHER COMPRISING A FORWARDLY EXTENDING PORTION CONNECTED TO THE REARMOST LEG AND HAVING AT ITS FORWARD END A FORWARDMOST LEG EXTENDING SUBSTANTIALLY AT RIGHT ANGLES TO THE FORWARDLY EXTENDING PORTION OF THE PIN, SAID FORWARDMOST LEG EXTENDING INTO A HOLE PROVIDED IN THE SHANK PORTION OF THE HOOKSHAPED MEMBER WHEREBY SAID TRIGGER-PIN IS RETAINED AGAINST ROTATION ABOUT THE AXIS OF THE REARMOST LEG OF SAID TRIGGER-PIN, SAID REARMOST LEG OF THE TRIGGER-PIN BEING ADAPTED TO BE WITHDRAWN FROM THE HOLE PROVIDED IN SAID ROD BY THE MOVEMENT OF AN ANCHOR LINE AGAINST THE FORWARDLY EXTENDING PORTION OF THE TRIGGER-PIN, THEREBY ALLOWING SAID ROD TO MOVE REARWARDLY ON THE FRAME ACTUATING THE FIRING MECHANISM AND DISCHARGING THE CARTRIDGE THEREBY CAUSING FORWARD MOVEMENT OF THE CUTTING MEMBER. 